thought it was a 2.8 when purchased, its a 3.4!

[dgsmooth]

howdy all, awsome site/forum here. well i'm a new fiero owner, just picked up a 86 gt for next to nothing as it had a bad engine knock/tick, which turned out to be a rod bearing. interesting part is that as i tore this engine apart and started measuring things to order parts, i found out its not a 2.8, but a 3.4. had the red 'fiero' upper intake plunum and everything so i never even asked. anyways my question is when a 3.4 has been put in place of a 2.8, where does the 2.8 end and the 3.4 begin? i know every conversion can be done differently, but typically speaking, would the computer and harness be fom the 2.8 still? what would need to be changed to put a 3.4 in place of the 2.8....would the intake have to be changed (ths one had the red 2.8 upper part at least)... would injectors ahve been changed, or would the 2.8 ones work? the cam had 4 failed lobed and that metal debris got into all bearings. luckily crank and pistons still in good shape, so i'm putting in all new bearings, a hone with new rings, new cam and lifters. i've ordered all that based on 3.4 an by size so thats all fine, but what led me down this question is the oil pressure sensor was broken off, so that got me asking wether i'd order the stock 2.8 fiero oil pressure sensor or order one from a 3.4? (or they might be the same). my guess would be the block, crank, pistons and rods, and heads would all be 3.4, then intake and everything else 2.8....i'm a heavy duty mechanic by trade so automotive/gas type intake systems not really my field of expertise. anybody who's savy with that stuff or has done a 3.4 conversion, i'd really appreciate a little advice or whatver insight anybody could throw at me. thanks to all and cheers for now.

[grandam455]

Good find, yes there is members here who can help you just give them some time and they will be able to answer you. Welcome to the site. Tom

[x-thumpr-x]

Hello
 The 3.4 is probably the easiest upgrade you can do to the Fiero with keeping the stock look. The block and internals are usually the only thing used in this swap and all other parts come from the original 2.8L motor. Then heads are the same between the motors also. If they kept the stock 3.4 oil pan, it has a oil level sensor that is no longer used. Most people have used the stock 15lb injectors with the swap and others have opted for 17lb or even the fords 19lb injectors. When you get into the 19lb range you should consider reprogramming the ECM, supposedly the ECM will run fine with 17lb injectors. 

We have a member her in Toronto that is currently building a 3.4L to go in his Fiero and another member in Lindsay who has already done this swap and little more to it. I take it you already ordered the camshaft? I have a stock 2.8L camshaft that was reground to match comp cams 2060 profile. It originally had a 396" lift, after work done it's now a 440" lift.  I built up a 2.8L when GM announced the closing of Pontiac all together. Motor lasted 30,000kms when all the rings went. Stay away from Engine Tech rebuild kits. They don't advertise there re ring kits are only meant for the pistons they sell.    Needless to say, I kept a lot of the good parts I put into the motor and sitting on a shelf right now. 

What other parts are you going to require?

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Greater Toronto Fieros